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Comment by monksy | Hacker News Reader

This is one of the frustrating things about what I have when I go to the doctor.

As a developer, I generally want a lot of information in order to pose theories about what is going wrong. They always seem really annoyed by this.

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One of my pet hates is that I have not been able to crack how to make doctors talk about probabilities quantitatively. It just seems to be impossible.

So far I have three theories why this is:

1. Med school teaches people that as they are just a little above God, they are always correct and do not need to care about probabilites.

2. MD's just do not understand probability and it is not taught in med school

3. Most patients have no clue about probability, can't stand uncertainty and they just want "the truth" from the doctor, who then calibrate their behavior according to that.

I kind of hope it is 3. but occasionally feel like it is 1 or 2.

I read When Breath Becomes Air, [0] the story of a physician-scientist's own battle with cancer, and one of the things he writes about was his frustration at getting treated like a patient when he was trying to get hard numbers for his survival probabilities.

It seems the consensus in the medical community is that there's very little good that can come from giving odds to a patient. What are you going to do with that information?

[0] https://www.goodreads.com/book/show/30241171-when-breath-bec...

> What are you going to do with that information?

Yep. Why on earth should I be given the means to make informed decisions about my body and life? What an outrageous idea.

(sarcasm included)

It's a very memorable experience when a doctor thinks he is helping by telling a person they are recovering from a terminal illness and they and their loved ones take him at his word and then go nuts trying to figure out why symptoms are getting worse.

That's the slippery slope you end up on when you say odds don't matter.

Or none of the above. So, you can apply statistics to medicine in the form of incidence of a disease, and likelihood ratios to increase or decrease the chance of disease in diagnosis. The problem is, the data for these is so difficult to interpret. Likelihood ratios in papers often have huge confidence intervals (like anywhere from 2-15), making their use problematic. Then often, they are quoted only for very specific patient groups, and applying them out of these groups invalidates the rule. Then things like prognosis are so variable, taking quantitively becomes a bit pointless. It’s especially true in cases where treatment or investigations are changing constantly, such as cancer. For diagnosis, the history is often more useful. Humans are story tellers, and the description of the problem varies hugely between patients, as does the significance of certain symptoms or descriptions. It’s an art to work out what is the real symptom and what isn’t. To work out the real picture isn’t always easy either.

Ultimately for things where there is relatively good evidence to practice statistics they are made into algorithms (see MDCalc for examples) but again it’s hard to apply them out of the correct patient population. Even these rules seem to poorly apply in many situations.

Then, real hard statistics rarely change management. You think of the reasonable causes and risk reduce as far as possible. Knowing the actual probability doesn’t really change what you can do. Same kind of goes for prognosis. Most patients don’t really know what to do with exact numbers (especially when they vary so much between different patients).

So, ultimately this is why doctors don’t use statistics regularly.

Sorry, but that is to me a textbook example of what I think as case 2.

It is not about hard statistics. It is your job to translate all those uncertainties and sources of knowledge to (subjective) probabilities. If you do not do that, you are doing things wrong. I do not see how there is anything to even discuss here. Probabilities are the current best tool we have to work with uncertainties.

I do not hire a doctor to just tell me what will be done. I hire a doctor as a consultant to give advice what he thinks is wise given his knowledge and then I do the decision what I do with my body and life. And the consultant should damn well give the best available information he has, just not think that I am so dumb that I can't decide myself.[1]

(Again, sorry for the rant, I have been way too frustrated on this specific issue earlier in my life)

[1] Obviously, most of the time I do agree with doctor's recommendations. But if I am one day having a cancer and a doctor refuses to estimate the odds for me living another month, year and decade, strong verbal abuse is given.

>...I kind of hope it is 3. but occasionally feel like it is 1 or 2.

Unfortunately #2 appears to be an issue for many doctors:

https://blogs.cornell.edu/info2040/2014/11/12/doctors-dont-k...

Mainly because it is genuinely exhausting for any medical practitioner. That lots of patients "enjoy" googling symptoms and coming up with far-fetched self-diagnoses is a given. But couple that with the perceived intellectual superiority of (software) engineers and you get a recipe for disaster. It's the equivalent of a doctor leaning over your shoulder while you're coding and telling you to remove random keywords.

Yeah I don't buy this.

Like any field I think there is a spectrum of quality and there are some really great doctors that know a lot, some really bad ones, and a lot of mediocre ones.

I've had a doctor (in the bay area) tell me that I should smoke a cigarette instead of having coffee if I'm having trouble sleeping, but want to keep working on something. Another talk positively about the butter coffee guy. I think the main reason they don't talk about a lot of options is probably time constraint and the common case being right most of the time. This means if you're actually not a common case you're probably better off investing your own time to try and figure things out too.

I like this article though, I think there is some similarity of style in troubleshooting software and disease diagnosis (just very different things to reason about).

I don't think it's as bad as removing random keywords, but given how limited resources are in medicine, I can see how a provider wouldn't want to explain why every individual's hypothesis is likely incorrect.

On the flip side, misdiagnoses are surprisingly common, and I think it's worthwhile for any provider to take a closer look if a patient has concerns.

If anything, I think this illustrates how much we need to reorganize and improve medicine. It's not like medicine is alone in this respect either, many sectors are inefficient, but when medicine is life altering and can be life or death, it's pretty high on the list IMO.

I think it’s because there’s a lot of ambiguity and “best guesses” in medical science and there’s no equivalent to programming documentation or manpages for medical treatment. Building code is for all intents and purposes a pretty objective and repeatable field of study. Whereas I would liken a medical treatment more to penetration testing because you’re trying to get an established logical system to accept new input/logic (medicine/procedures) rather than trying to build a logical system from scratch (or with building blocks)

Everybody feels the same way - mechanics feel exactly the same. IT tech support people feel the same.

And, you know, it seems like an increasing number of medical professionals just defer to whatever the patient wants anyway. What's the point of saying you're the expert if you won't be the expert?

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